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11, 1 9 J. FORTE EI'AL 2,899,655

COIL BOBBIN AND LAMINATION KEEPER Filed April 26. 1957 3| j 3| a| a:

i l2 as :4 '4 u 25 I I2 [1'4 a I zs I5 30 t2? 3: I154 nvmvroxs 0.1. FORTE JOHN A. WOLFE ATTO/ME'Y United States Patent ()fiice 2,899,655 Patented Aug. 11, 1959 COIL BOBBIN AND LAMINATION KEEPER Donald J. Forte, Robbinsdale, and John A. Wolfe, Roseville, Minn., assignors to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn., a corporation of Delaware Application April 26, 1957, Serial No. 655,298

6 Claims. (Cl. 336-198) The disclosed invention is directed to a coil bobbin and lamination keeper means, and more specifically is directed to such a means for a highly compact magnetic amplifier that can be conveniently used with printed circuits.

In the fabrication of magnetic amplifiers two general types of cores and associated structures are used. The first type of core is the toroidal core, while the second is the more conventional type of core fabricated from punched laminations which have a plurality of legs and an integral yoke member. The present invention is directed to the second type or construction of magnetic amplifier.

Where magnetic amplifiers are fabricated utilizing cores manufactured from punched laminations it is the normal practice to utilize prewound coils and to insert the laminations into a stacked relationship through the openings in the center of the coils. After the insertion of the laminations some means is normally supplied to hold the laminations in a compact relationship. In most cases this is accomplished by the insertion of rivets or bolts through the stack of laminations so that the magnetic structure is held rigidly in place. It will be appreciated that this method of fabricating the magnetic structure of the magnetic amplifier adds to its weight and bulk and is therefore undesirable. Localized mechanical stresses on laminated structures further change the magnetic properties of the laminations and should be avoided. This type of arrangement also creates certain problems where it is desired to mount the magnetic amplifier on printed circuitry in a compact manner.

It is the primary object of this disclosure to present a magnetic amplifier bobbin and integral lamination keeper which forms an exceedingly compact structure that does not place localized mechanical stresses upon the laminations but does hold them in a firm, uniform manner.

A further object of the present invention is to disclose a magnetic structure and coil which can be fabricated having a minimum number of parts.

Still a further object of this invention is to present an electromagnetic coil and core which can be mounted directly on a printed circuit.

Yet another object of this disclosure is to present a bobbin and lamination keeper for a magnetic amplifier which provides mounting space for the rectifiers associated with the magnetic amplifier.

These and other objects will become apparent when the single sheet of drawings is considered with the fol- 2 lowing specification. The single sheet of drawings contains a plurality of figures, wherein:

Figure 1 is a front view of the coil and core of a magnetic amplifier;

Figure 2 is a side view of Figure 1;

Figure 3 is a top view of Figure 1;

Figure 4 is a cross-section of Figure 1 along the lines 44; and

Figure 5 is a schematic representation of a typical magnetic amplifier circuit which can be utilized with the structure shown in Figures 1 through 4.

In the Figures 1 through 4 there is generally disclosed the winding form and windings of a magnetic amplifier. The bobbin generally disclosed at 10 is formed of any convenient material which can be cast or molded, and is specifically disclosed as an insulative type of plastic. This bobbin contains a central winding form 11 and two end members 12 and 13. The winding form 11 is substantially rectangular in shape and extends outwardly at 14 and 15 to the full width of the end members 12 and 13. The center section 17 of the form 11 provides a winding surface for the coils 16. The end members 12 and 13 have sides 20 and 21 which form with the center section 17 a complete winding recess for the coils 16.

The end members 12 and 13 further have outer peripheral walls 22 and 23 which extend around the entire periphery of the end members 12 and 13. The peripheral walls 22 and 23 of the end members 12 and 13 define with the form walls 14 and 15 four cavities 24 through 27. The cavities 24 through 27 are substantially rectangular and their function will appear below.

A plurality of E-shaped laminations 30 are inserted into the bobbin 10. The laminations have their center legs passing through portion 17 of the form while the yokes are retained by the members 14 and 15 which complete the outer ends of the winding form 11. It will thus be seen that when the plurality of laminations 30 are inserted into the form 11 that the core holds not only the center leg thereof in place but also locks the yoke portions of the E-shaped laminations into an abutting relationship. When the center section 17 has been stacked full, the laminations are held fixedly in place due to their frictional engagement with each other and the walls of the center section 17 as well as with the walls 14 and 15 of the yoke retaining sections. It will thus be seen that the stack of laminations 30 can be placed into the bobbin 10 in such a manner that a compact magnetic structure is formed within the coils 16.

The circumferential portions 22 and 23 of the bobbin further support a plurality of terminal pins 31. These pins are held in place by inserting the pins 31 through holes in the circumferential sections 22 and 23. Each of the pins 31 forms a terminal for the coils 16. This will become more apparent when the representative schematic of Figure 5 is discussed in connection with the presently disclosed physical structure.

The cavities 24 through 27 are provided as recesses for electrical components that are associated with the magnetic amplifier or other associated circuitry. Each of the cavities 24 through 27 can contain one or more electrical components that are used in the associated circuitry with the device disclosed herein. The electrical components that are inserted in cavities 24 through 27 are placed such that their electrical lead wires project outward from the cavities in a manner similar to the terminal pins 31. It will thus be appreciated that the bobbin It) and any components which are embedded in the cavities 24 through 27 may be placed on a printed circuit and attached thereto. If a device is used with the printed circuit it is further obvious that once the device has been attached to the printed circuit that the excess length of the terminal members is conveniently removed.

In Figure there is represented a schematic for a biasing single-core self saturating magnetic amplifier. This amplifier utilizes the laminations 30 in the manner described above. Around the central leg of the laminations there are placed three coils 16A, 16B, and 16C. Winding 16A is a load winding, winding16B is abias winding, and winding 16C is a control winding. It will be appreciated that the windings 16A, B, and C in total make up the coils 16 shown in Figures -1 through 5. The winding 16A further has two lead wires 32 and 33 which are attached to terminal pins 31. The winding 16Bhas lead wires 34 and 35 which are also attached to other terminal pins 31. The winding 160 has lead wires 36 and 37 which extend to the bottom of thedeviceshown in Figures 1 through 4 and areattached to theterminal pins 31 and associatedtherewith.

The circuitry of the magnetic amplifier is completed by the addition ofaload resistor 40, a loadrectifier 741, a bias resistor 42, anda bias rectifier 43. It is understood that any of the components 40 through 43 could be placed in one ofthe cavities 24 through 27 and could be inter-connected either by conventional electrical circuitry or by means of a printed circuit slipped over the terminalsfil and the lead wires associated with the com ponents 40 through 43.

With the device disclosed it is obvious that a compact type of magnetic amplifier utilizing a single bobbin and lamination keeper has been disclosed. While the unit has not been specifically disclosed in the drawings as mounted on a printed circuit it is obvious that its use could be coupled therewith. It is also obvious to those skilled in the art that the present structure could be modified in many ways within thescope of the invention and it is therefore understood that the disclosure contained in Figures 1 through 5 is merely representativeof one of the many possible embodiments. While the device has been disclosed specifically in use with a magneticv ainplifier it could be incorporated in inductive devices of all types such as chokesand transformers. Withthis in mind, the applicant wishes to be restricted in vhisinvention only to the scope of the appended claims.

I claim as my invention: i

1. In an apparatus of the classdescribed: a plurality of magnetic laminations having legs and yokes; winding and lamination support means including a winding form and two enlarged integral end members having an'opening therethrough; said end members being substantially the same width as said lamination yokes and having said opening therein rectangular in shape; .the length of said opening in the end members corresponding with the length of said yokes; and electric coil means wound on said winding form of said support means; said yokes and at least one leg of each lamination positioned in said opening wherein said laminations are held in a clamped relationship; said rectangular opening in said end members holding said yoke members; said laminations completing a magnetic circuit linking said electrical coil means.

2. In an apparatus of the class described: a plurality of magnetic laminations having legs and yokes; winding and lamination support means including a windingfor-m and two enlarged integral end members having an opening therethrough; said end members being substantially the same width as said lamination yokes and having said opening therein rectangular in shape; the length of said opening in the end members corresponding with the length of said yokes; terminal means projecting through said end members; electric coil means Wound upon said winding form of said support means; and connection means joining said coil means and said terminal means; said yokes and at least one leg of said laminations positioned in said opening wherein said laminations are held in a clamped relationship; said rectangular opening in said end members holding said yoke members; said laminations completing a magnetic circuit linking said electrical coil means.

3. In an apparatus of the class described: a plurality of magnetic laminations having legs and yokes; winding and lamination support means including a winding form and two enlarged integral end members having an opening therethrough; said end members being substantially the same width as said lamination yokes and having said opening therein rectangular in shape; the length of said opening in the end members corresponding with the length of said yokes; said end members further having cavity means therein adjacent to said opening; electric cornponent meansinserted in said cavity means and retained within the width of said end members; terminal means projecting through said end member's; electric coil means wound upon said winding form of said support means; and connection means electrically connecting said component means and said coil means to said terminal means;

said yokes and at least one leg of each lamination posi-- tioned in said opening wherein said laminations areheld in a clamped relationship; said rectangular opening in said end members holding said yoke members; said laminations completing a magnetic circuit linking said electric coil means.

.4. In a. saturable'reactor: a plurality of magnetic laminations .having legs and yokes; winding and lamination support means including a winding form and two enlarged integral endmembers having an openingtherethrougl1; said end mem bers being substantially thesame width as said lamination yokes and having said opening therethrough rectangular in shape; the length of said opening in the end members corresponding with the length of ,said yokes; said end members further having cavity means thereinadjacent to said openingpelectric component means inserted in said cavity means and retained within the width of said members; terminal means projecting through said end members; reactor coils wound on said winding form of said support means; and connection means connecting said component means and said reactor coils to said terminal means; said yokes and at least onelegiofeach laminationpositioned in said opening wherein said laminations are held ina clamped "relationship;saidrectangular opening in said end'rne'mbers holding said yoke members; said laminations completing ajrnagnetic circuit for said saturable'reactor and linking saidreactor coils. l

5. In }a saturable reactor: a plurality of E -shaped magnetic laminations. having legs and yokes; a winding and lamination support bobbin'including a winding form and two enlarged integral end members having an opening therethrough; said endmembers being substantially thesame width as said lamination yokes and having said openings therein rectangularin shape; the length' of said opening in theend members corresponding lwith the length of said yokes; terminal pins projecting through said end members; reactor: coils woundon said winding form of said support gbobbin; and connection means joining said reactor coilshnd said terminal pins; said yokes and the center leg of each lamination positioned injs'aid opening wherein said laminationsarehld in a clampedrelationship; said rectangular lop ening'in said end fiiie'mbers holding" said yoke'rr'iemb'ers'; said laminations completing a magnetic circuit linking' said reactor coils. V

6. In a saturable reactorf a a plurality of E-shaped magnetic laminations having legsand yokes; a winding and lamination support bobbin including a winding form and two enlarged integral end members having an open ing therethrough; said end members being substantially the same width as said lamination yokes and having said opening therein rectangular in shape; the length of said opening in the end members corresponding with the length of said yokes; said end members further having cavities therein adjacent to said opening; electrical components inserted in said cavities and means retaining said components within the width of said end members; terminal pins projecting through said end members; reactor coils Wound upon said winding form of said support bobbin; and electrical connection means connecting said components and said coils to said terminal pins; said yokes and the center leg of each lamination positioned in said opening wherein said laminations are held in a clamped relationship; said rectangular opening in said end members holding said yoke members; said laminat-ions completing a magnetic circuit linking said reactor coils.

References Cited in the file of this patent UNITED STATES PATENTS 

